Larry Sanger writes: "In 2011, the Wikimedia Board committed to installing a "controversial content" filter even weaker than Google's SafeSearch, as proposed by the "2010 Wikimedia Study of Controversial Content." Since then, after growing opposition by some Wikipedians, some board members have made it clear that they do not expect this filter to be finished and installed. Nevertheless, as TFA makes clear, Wikipedia continues to host an enormous amount of extremely gross porn and other material most parents don't want their kids stumbling across. And this content is some of the website's most-accessed. Nevertheless, children remain some of Wikipedia's heaviest users. Jimmy Wales has recently reiterated his support for such a filter, but no work is being done on it, and the Foundation has not yet issued any statement about whether they intend to continue work on it."

Without the image filter (something all other major sites have) if you search on Wikipedia or Wikimedia Commons for normal, everyday items such as' necklace', 'toothbrush' or, in French, 'homework' (devoir) you get as your top or second hit, porn.
Children are encouraged to use these resources.
Teens are often admin on these sites, cataloging and categorizing the porn.
Yech.